code: def __call__(self, image, target):
      w, h = image.size
  
      image_id = target["image_id"]
  
      anno = target["annotations"]
  
      anno = [obj for obj in anno if obj["iscrowd"] == 0]
  
      boxes = [obj["bbox"] for obj in anno]
      # guard against no boxes via resizing
      boxes = torch.as_tensor(boxes, dtype=torch.float32).reshape(-1, 4)
      boxes[:, 2:] += boxes[:, :2]
      boxes[:, 0::2].clamp_(min=0, max=w)
      boxes[:, 1::2].clamp_(min=0, max=h)
  
      classes = [obj["category_id"] for obj in anno]
      classes = torch.tensor(classes, dtype=torch.int64)
  
      segmentations = [obj["segmentation"] for obj in anno]
      masks = convert_coco_poly_to_mask(segmentations, h, w)
  
      keypoints = None
      if anno and "keypoints" in anno[0]:
          keypoints = [obj["keypoints"] for obj in anno]
          keypoints = torch.as_tensor(keypoints, dtype=torch.float32)
          num_keypoints = keypoints.shape[0]
          if num_keypoints:
              keypoints = keypoints.view(num_keypoints, -1, 3)
  
      keep = (boxes[:, 3] > boxes[:, 1]) & (boxes[:, 2] > boxes[:, 0])
      boxes = boxes[keep]
      classes = classes[keep]
      masks = masks[keep]
      if keypoints is not None:
          keypoints = keypoints[keep]
  
      target = {}
      target["boxes"] = boxes
      target["labels"] = classes
      target["masks"] = masks
      target["image_id"] = image_id
      if keypoints is not None:
          target["keypoints"] = keypoints
  
      # for conversion to coco api
      area = torch.tensor([obj["area"] for obj in anno])
      iscrowd = torch.tensor([obj["iscrowd"] for obj in anno])
      target["area"] = area
      target["iscrowd"] = iscrowd
  
      return image, target
  
file_path: vision/references/detection/coco_utils.py
imports: import os
  import torch
  import torch.utils.data
  import torchvision
  import transforms
  from pycocotools import mask
  from pycocotools.coco import COCO
label_desc: Use image node_id 1 for calling the ConvertCocoPolysToMask obj's underlying member method code with example usage: obj.__call__(image, target) and returns: image,  target